RU2441257C1 - Vibration action seismic exploration system - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: seismic exploration system has a vehicle with an enclosed space, a cylindrical tray with an impact plate which can move downwards through a manhole at the bottom of the vehicle, a heavy piston, guides for vertical movement of the piston and the tray, cam-type vibrator placed between the tray and the piston and an electric motor with controlled rotational speed for the vibrator. The rotational speed of the shaft is controlled, which enables to obtain seismic signals of different frequencies.

EFFECT: high frequency of the seismic signal.

3 dwg

Description

The invention relates to the field of geophysical exploration of minerals, mainly for oil and gas.

A known source of seismic signals (seismic acquisition complex - SRK) of vibration action according to the patent of the Russian Federation No. 2313805 of 03/09/2004, IPC G01V 1/155 / 1 /. The seismic exploration complex (SRK) includes a vehicle (car or ship) with an enclosed space, a source (generator) of vibrational-type seismic signals (vibrations), rigidly fixed to the body parts of the floating vehicle, a cylindrical pallet (container) with a plate, which is pulled out of the room through the hatch in the bottom, and mechanisms for raising and lowering the pallet. When the generator is operating, the pallet plate vibrates on the medium (water, soil). As a source of seismic vibrations of the vibrational type, the domestic vibrator SV-5-150M or the vibrator of the Petro Alliance company MERTZ-18ND can be used, creating a compression force of up to 10 tons with an amplitude of 5-8 centimeters.

A device for creating seismic signals in an aqueous medium according to the patent of the Russian Federation No. 2345386 dated January 27, 2009, IPC G01V 1/02. / 2 /. The device includes a floating means with a hold, a metal plate rigidly fixed in the opening of the bottom of the PS, a vibration generator and a striker with a striker. Here, a seismic signal in an aqueous medium is created due to sound vibrations of a fixed steel plate having direct one-way contact with this medium after hard impacts of the hammer.

The disadvantage of the device according to the patent of the Russian Federation No. 2345386 from 01/27/2009 is the inverse effect on the floating means from the acceleration of the striker, equal in power to the direct. The reverse effect leads to the appearance of seismic signals from the bottom of the PS, which creates interference in the seismic signal from the plate.

Known existing source of seismic signals "Dinoseis" (USA). He works on an explosive gas mixture; placed under the bottom of the vehicle (TS), has an explosive chamber with a diameter of 1.5 m and a rod for attachment to the bottom of the vehicle. Before work, he lowers the bottom of the chamber to the ground. When the source is triggered, it acts on the bottom of the chamber with tremendous force, and the rod acts on the bottom of the vehicle with the same effort. To reduce this effect, an additional load of 5000 kg is placed on top of the rod. The disadvantage of this type of source is the need to use additional load on the piston.

Known seismic exploration complex (SRK) according to the patent of the Russian Federation No. 2272302 dated 03/20/2006, IPC G01V 1/155 / 3 /, used to create impact on the environment (soil, water). SRK contains a vehicle (TS) with a closed room, a cylindrical pan with a shock plate, pulled out of the room through the hatch in the bottom, a heavy plunger and mortar located between the pallet and plunger. The mortar plunger is a non-flying “mine”. When a mortar is fired, the plunger receives a small speed (5-6 m / s), "jumps" up to a height of 1.5-2.5 m and falls back. A shock plate pallet acts on the medium (soil, water) and creates a seismic signal. When firing, when the plunger moves up, when the pallet moves down and when hit, no vertical impacts are exerted on the vehicle.

As a prototype, a source of seismic signals (vibrations) of a vibrational type is adopted according to the patent of the Russian Federation No. 2313805 dated 03/09/2004, IPC G01V 1/155 / 1 /.

The disadvantage of the prototype is the rigid fastening of the oscillation generator with the details of the body of the floating vehicle, creating the conditions for the reverse effect of a powerful oscillation generator on the vehicle. This is especially evident in the land version of the source. Here, the impact on the ground with a preload force of 10 tons leads to the same strong reverse impact on the vehicle, which leads to a sharp vertical movement (jump) of the vehicle and interferes with the main seismic signal. In addition, the existing vibrators, both domestic SV-5-150M, and the Petro Alliance vibrator MERTZ-18ND, are very bulky, have a lot of weight and require a lot of space to accommodate.

The aim of the invention is to eliminate the feedback of a powerful vibrator on the vehicle, increasing the purity of the seismic signal and significantly improving the overall mass characteristics of the SRS.

This goal is achieved by the fact that:

- a new element is added (introduced) to the design of the vibrating seismic survey complex according to the RF patent No. 2313805/1 / (prototype) - a heavy plunger, known from RF patent No. 2272302 dated 03.20.2006 / 3 /, and

- a cam type vibrator with a controlled frequency of impacts is used as a vibrator.

The diagram of the seismic survey complex is shown in the drawings of figures 1, 2, 3. In figure 1 (land seismic survey complex) is indicated: 1 - plunger; 2, 3, 4 - pallet, plate and pallet bracket; 5, 6 - shaft and cam; 7, 8 - traction and spring mechanism; 9 - a directing pipe; 10 - mechanisms for raising and lowering the pan with a mortar; 11, 12 - the bottom and ceiling of the vehicle. In Fig.2 (cam vibrator) is indicated: 1 - plunger; 2, 4 - pallet and pallet bracket; 5, 6 - shaft and cams of the vibrator; 13 - Hook joint; 14 - rotation motor. Figure 3 (diagram of the cam vibrator at the time of maximum movement of the plunger up) is indicated: 1, 2 - the plunger and the pallet; 5, 6 - shaft and cams of the vibrator. The amplitude of the change in the distance between the plunger and the pallet is in the range of 5-8 centimeters, with half of the range being the free fall of the plunger, which is clearly seen in figure 1 from positions 1, 2, 5, 6. The shaft 5 and cams 6 are rotated with using an electric motor with a controlled speed of rotation.

When the vibrator is operating, a seismic signal (punch of the pallet plate on the ground) is generated twice in half a revolution of the shaft 5: the first quarter of the turn is a sharp rise of the plunger by the magnitude of the amplitude with the punch of the pallet plate on the ground, and the second quarter of the turn is the free fall and impact of the metal plunger on the fixed metal end of the pallet with repeated impact of the plate on the ground. The rotation speed of the shaft 5 is adjustable, which allows you to receive seismic signals of various frequencies and purities.

The cam vibrator, as can be seen in figure 2, is simple in design, has small dimensions and light weight. All sharp vertical, oppositely directed movements of the plunger and the pallet do not have any reverse effect on the vehicle. Using this type of vibrator, it is possible to create seismic acquisition complexes of vibrational action of various capacities depending on the mass of the plunger and engine power.

The implementation of the RMS in this way, as shown in the drawings, eliminates the reverse effect of a powerful vibrator on the vehicle, improves the purity of the seismic signal and significantly improves the overall mass characteristics of the seismic survey complex.

Claims (1)

A vibrating seismic system, including a vehicle, a vibrator, an energy source for a vibrator and a pallet with a shock plate, pushed down through the hatch in the bottom of the vehicle, characterized in that it additionally uses a heavy plunger that performs a reciprocating movement as a vibrator a cam type vibrator is used with a plunger movement amplitude of 5-8 cm, and an electric motor with a controlled rotational speed is used as a power source for the vibrator tions.

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